Method, system and apparatuses for the transmission of data on electric network

ABSTRACT

There are described a method and a system for the transmission/reception or communication of data and/or information on electric line between two electronic control devices, including: an electric user (HA), in particular a household appliance, having a first electronic control system asnd at least a first electric load; a monitoring or control device (SA), having a second electronic control system, said device (SA) being located on said line between an electric power source and said first electric load. According to the invention, the transmission/reception or communication of data and/or information on said line is realized by means of an electric power modulation between said user (HA) and said device (SA), and/or vice-versa.

DESCRIPTION

[0001] The present invention relates to a method, a system andrespective means for the transmission or communication of data and/orinformation on an electric line between two devices having respectiveelectronic control systems.

[0002] The need of transmitting data or information using the electricnetwork as a communication means has been known for a long time; thisnecessity is particularly felt in the so-called home automation ordomotic field, where the dialog among different electric users maygenerate significant benefits in terms of energy saving and improvedtotal performance.

[0003] The fact that the same electric network can perform also the roleof bi-directional communication line allows for avoiding the need ofemploying an additional wiring system, and also ensure a full access toall electric users, even if distributed in relatively distant orlocations being difficult to access to (such as a garage, an attic, acellar, etc.).

[0004] The most common data transmission systems on electric network arebased on the use of the so-called power line, which use appropriatemodems capable of transmitting and receiving information throughspecific modulation and demodulation of small electric signals beingoverlapped on the mains voltage, respectively.

[0005] The two modulation techniques most commonly used are known as FSK(Frequency Shift Keying) and ASK (Amplitude Shift Keying), which arebased on a particular frequency or amplitude modulation, respectively.Power line transmission systems based on FSK modulation highlight ahigher sturdiness to electric noise compared to the systems based on ASKmodulation; however, the relevant modems are more expensive. In bothcases, anyway, the cost for implementing the communication system in ahousehold electric appliance is usually too high to be directly borne bya household electric user, such as a washing machine, a refrigerator, aniron, an electric stove, and so on.

[0006] As a result, the so-called communication node, i.e. the elementallowing lie information exchange on the electric network between ahousehold user and other external apparatuses cannot be incorporatedinside the household appliance itself due to cost reasons, but should beproposed as an optional device to be managed separately.

[0007] However, this involves a higher cost also for the control systemof the electric user, for which an electronics having appropriateinterfaces for the likely dialog with the communication node isrequired, as well as an appropriate mechanical housing for the latterwithin the electric user.

[0008] For this reason, the concept of communication on electric networkconcerns, as a matter of fact, only high-priced electric users, i.e.pertaining to higher model ranges, capable of bearing its unavoidablecost increase, whereas it is substantially precluded to mass production.

[0009] From U.S. Pat. No. 5,493,267 an arrangement is disclosed, for thetransfer of control commands to a working means in an apparatus, via awire also used for the power supply to said working means. Thearrangement comprises a control unit provided for creating a controlcommand by suppressing, in a predetermined order, at least part of oneor several consecutive half-periods of a predetermined polarity of thesupply voltage. Moreover, the arrangement comprises a slave unit 11)operating in response to the control command transmitted to activateworking means. The control unit has such a design that before a controlcommand is transmitted the control unit operates to shortly disconnectthe supply voltage on the wire for a period of time required for thecurrent in the working means to decline essentially to zero.

[0010] The present invention has the arm of solving the above drawbacksand, in particular, to provide a method, a system and respective meansfor the transmission or communication of data or information on electricnetwork, which are alternative and/or complementary to the previous onesand which can be implemented at a low cost on the mass production ofhousehold electric users, in particular household appliances.

[0011] These and further objects, which will become more apparent in thefollowing, are attained according to the present invention by a method,a system and relevant means for the transmission or communication ofdata or information on electric network having the features of theannexed claims, which are intended as an integral part of the presentdescription.

[0012] The transmission/reception of data on electric network accordingto the present invention relates in particular to the exchange of binaryinformation between two electric apparatuses, through two modulation anddemodulation techniques, which may be complementary between each other.

[0013] The data transmission technique on electric line according to thepresent invention uses, as coding means for the binary information to betransmitted, appropriate controlled interruptions or suspensions of theelectric network, called in the following “network interruptions” or“voltage interruptions”, obtained through solid state switches, such astriac.

[0014] The second data transmission technique on electric line accordingto the invention uses, as coding means for the binary information,“controlled power absorptions”, also obtained through solid stateswitches (triac).

[0015] In both cases the binary information are coded through aparticular form of “power modulation” which forms the main core of thepresent invention; therefore, the two above transmission techniques willbe identified in the following as “modulation of the supplied power” and“modulation of the absorbed power”, respectively. It is clear that,beside the data coding obtained through power modulation, appropriatedemodulation circuits will be provided for decoding the received data.

[0016] The two above transmission techniques on electric line can beadvantageously employed, according to the present invention, either in asingle mode or in a combined mode.

[0017] A first advantageous example of use of the present invention,using the combination of the two cited data transmission techniques onelectric line, concerns the communication between two electroniccontrolled apparatuses, represented by a respective electric user, whichwill be indicated with HA (Home Appliance), and a device for monitoringthe operation of the same electric appliance, indicated with SA (SmartAdapter).

[0018] A second significant example of use of the present inventionconcerns a possible aggregation of several electric users HA to one samemonitoring device, called MSA (Multiple Smart Adapter), which isappropriately prearranged for the purpose.

[0019] Finally, a third example of use of the present invention concernsthe specific field of household appliances having a low absorption ofelectric power (such as refrigerators, freezers, gas hobs, gas boilers,and so on), where even the implementation of the modulation/demodulationof the absorbed power technique only is particularly advantageous, i.e.the technique based on the controlled absorptions of electric power.

[0020] Further aims, features and advantages of the present inventionwill become apparent from the following detailed description made withreference to the annexed drawings, which are only supplied by way of nonlimiting example, wherein:

[0021]FIG. 1 shows the mode of connection, according to the presentinvention, between a monitoring device SA (Smart Adapter) and a genericelectric user HA (Home Appliance);

[0022]FIG. 2 shows an example of a transmission stage or transmitter ofbinary information, being comprised in the control system of themonitoring device SA of FIG. 1, using the modulation of the suppliedpower (power modulation: source mode) to the electric user HA, accordingto the present invention;

[0023]FIG. 3a shows an example of a reception stage or receiver ofbinary information, being comprised in the control system of theelectric user HA of FIG. 1, using the demodulation of the supplied power(power demodulation: source mode) to the user HA through the monitoringdevice SA, according to the present invention;

[0024]FIGS. 3b, 3 c and 3 d illustrate three further possibleembodiments of a receiving stage of binary information being comprisedin the control system of the electric user HA of FIG. 1, each one usingthe demodulation of the supplied power (power demodulation: source mode)to such a user through the monitoring device SA, according to thepresent invention;

[0025]FIG. 4 shows an example of a transmission stage or transmitter ofbinary information being comprised in the control system of the electricuser HA of FIG. 1, using the modulation of the absorbed power (powermodulation: sink mode) from the same user, according to the presentinvention;

[0026]FIG. 5 shows an example of a receiving stage or receiver of binaryinformation being comprised in the control system of the monitoringdevice SA of FIG. 1, using the demodulation of the absorbed power (powerdemodulation: sink mode) from of the electric user HA according to thepresent invention;

[0027]FIG. 6a shows a flowchart describing a generic transmission ofdigital information using the power modulation technique according tothe present invention; this flowchart can be associated to both thetransmission techniques (FIGS. 2 and 4) which are the object of thepresent invention;

[0028]FIG. 6b shows a flowchart associated to the receiving stage ofdigital information using the power modulation technique according tothe present invention; this flowchart can be associated to bothreception techniques (FIGS. 3 and 5), which are the object of thepresent invention;

[0029]FIG. 7 shows a block diagram of a possible physical embodiment ofthe monitoring device SA of FIG. 1;

[0030]FIG. 8 shows a block diagram of a particular embodiment of amonitoring device capable of dialog with several electric users,according to the invention;

[0031]FIG. 9 shows an example of an advantageous use of the monitoringdevice of FIG. 8;

[0032]FIG. 10 shows a particularly advantageous use wherein an electricuser HA, represented by a refrigerator, uses only the transmissiontechnique based on the modulation/demodulation of the absorbed power(sink mode) according to the invention, for systematically transmittinginformation to the external environment, using its own supply cord.

[0033] As previously mentioned, the object of the present invention,relating to the transmission or exchange of binary information betweentwo electronically controlled apparatuses, can be obtained through twodifferent modulation and demodulation techniques, which will bedescribed separately in the following, with a general reference to theannexed FIG. 1.

[0034] Said FIG. 1 describes the way of connection between a monitoringdevice, indicated with SA (Smart Adapter) and a generic householdelectric user, indicated with HA (Home Appliance).

[0035] The device SA, which is interposed between a current outletindicated with “Outlet” in FIG. 1 and the electric user HA, is a deviceperforming a monitoring and control function of the electric useritself, it can be assumed, in general terms, that the monitoring deviceSA is of the type described in U.S. Pat. No. 4,644,320 or EP-A-0 550263.

[0036] 1. First Technique of Data Transmission/Reception on Electric

[0037] Network: Modulation of the Supplied Power

[0038] A first technique of data transmission/reception on electricnetwork according to the present invention uses, as coding means for thebinary information, appropriate controlled lacks or interruptions of theelectric mains, which are called hereinafter as network interruptions orvoltage interruptions; this technique is featured by the two followingessential elements:

[0039] a transmitter, capable of generating network interruptions orvoltage interruptions in accordance with the binary information to betransmitted; a possible circuit diagram of said transmitter isillustrated in the upper part of FIG. 2;

[0040] a receiver, capable of detecting and decoding said networkinterruptions; a possible circuit diagram of said receiver isillustrated in the upper part of FIG. 3a. Possible variant embodimentsof this receiver are illustrated in the upper part of FIGS. 3b, 3 c and3 d.

[0041] The technique of data transmission/receiving on electric networkbased on the modulation/demodulation of the supplied power according toa basic implementation of the present invention provides for theassociation of one bit to each half-wave of the mains voltage;conveniently, a fixed time, such as 5 mSec may be assigned to everynetwork interruption (relating to each half wave), or another moreappropriate value also in view of the application in use. Therefore,considering that the mains frequency is 50 or 60 Hz (Europe/USA, Japan),the data baud rate equals 100 or 120 bps (bits per seconds),respectively. 1.1 Description of the transmitter for the networkinterruptions technique The description of the transmitter for thenetwork interruptions according to the present invention relates to FIG.2.

[0042] According to the basic version of the present invention, thetransmitter associated to the control system of the monitoring device SAgenerates network interruptions, being of controlled duration within apredetermined time interval, by means of a solid state switch or relay,being represented by the triac T in FIG. 2, whose actuating signal G(applied to the gate of the triac T) is appropriately synchronized witha signal ZD which detects the zero-crossing of the mains voltage.

[0043] The triac T is arranged in parallel to the normally closedcontact RC of an appropriate electromechanical relay, capable ofmanaging the current flow to the electric user HA when there is no needfor data transmission, i.e. no needs of generating network*interruptions. Moreover, the triac T has the further purpose ofprotecting the same contact RC, by intervening every time before itswitches, to avoid sparking (photo-voltaic arc) and its consequent wear.This is obtained by switching the contact RC of the relay always withthe triac T being closed (enabled), according to a procedure known tothe man skilled in the art, which can be summarized in the sequence ofthe following three operations:

[0044] 1. closure of the triac T;

[0045] 2. energization (or de-energization) of the coil of the relay RC;

[0046] 3. opening of the triac T after the contact of the relay RC hasterminated its switching operation, reaching a stability state (nocontact bouncing).

[0047] The relay RC, the triac T and the synchronism signal ZD aremanaged by a microcontroller indicated with M1 in FIG. 2.

[0048] As to the coding logic of the binary data to be transmitted, twopossible procedures are provided according to the basic version of thepresent invention:

[0049] positive logic coding: a logic “1” corresponds to the presence ofa network interruption and a logic “0” corresponds to the absence of thesame in the period of time being provided for the data transmission;

[0050] negative logic coding: a logic “0” corresponds to the presence ofa network interruption and a logic “1” corresponds to the absence of thesame in the period of time being provided for the data transmission.

[0051] The graph chart illustrated in the lower part of FIG. 2highlights by mere way of non limiting example the transmission of asequence of 8 bit, using a positive logic coding, wherein the durationof the network interruptions associated to the logic “1s” equals afourth of the mains period (5 mSec, should the mains frequency be 50Hz).

[0052] This bits sequence is preceded by a transmission start signalindicated by “Start” which, by way of non limiting example, isrepresented by a network interruption lasting a mains half cycle (10mSec, should the mains frequency be 50 Hz).

[0053] The upper part of the graph chart in FIG. 2 indicates a temporarysequence of the alternated half-waves of the mains voltage (voltage Aapplied to the user HA by the device SA—see upper part of FIG. 2),whereas the lower part of the graph chart of FIG. 2 indicates the pulsesof the signal G applied by the microcontroller M1 to the gate of thetriac T, according to the logic level of each bit to be transmitted.

[0054]FIG. 6a represents, by way of non limiting example, a flowchartindicating a possible communication protocol to be adopted fortransmitting digital information on electric network according to theembodiment of the present invention illustrated in FIG. 2.

[0055] Block 1 of this flowchart is a start block; block 2 is a testblock, wherein the control program checks the likely start condition ofthe transmission. If the start condition of the transmission is notverified, the control remains at block 2, otherwise it passes to block3.

[0056] Block 3 is a test block, wherein the control program searches thesynchronism condition with the zero-crossing of the mains voltage. Ifthe synchronism condition is not verified, the control remains at block3, otherwise it goes on to block 4, where the transmission starts.

[0057] Blocks 4, 5 and 6 represent schematically, by way of non limitingexample, the following three phases of the transmission of binary data:

[0058] 1. sending of the signal (ST of start of transmission, i.e. thesignal indicated with “Start” in FIG. 2;

[0059] 2. sending of a fixed sequence of bits which is associated to thedigital information to be transmitted;

[0060] 3. sending of the checksum control signal relating to thetransmitted sequence of bits.

[0061] Once the checksum has been sent, the control goes over to block7, which is a test block in which an acknowledge signal ACK is waited ofthe correct reception by the control system of the receiving electricuser HA of FIG. 2.

[0062] If there is no ACK signal, the control goes over to block 8,which is a test block checking the achievement of a determined time-out,within which the signal ACK by the receiving device HA should arrive.

[0063] If the signal ACK does not arrive within the maximum pre-settime-out, the control goes back to block 3 for a complete repeat of thetransmission, whereas, if the above signal of correct reception arriveswithin the pre-set time-out, the control is released to block 9, whichis a block of transmission end.

[0064] 1.2 Description of the Receiver for the Network InterruptionsTechnique

[0065] The description of the receiver of network interruptionsaccording to the present invention refers to FIGS. 3a, 3 b and 3 c,wherein three possible circuit embodiments are illustrated by way of nonlimiting example, respectively.

[0066] A first circuit embodiment of the receiver of networkinterruptions according to the basic version of the present invention isrepresented in FIG. 3a, where TF (Transformer) indicates a standardtransformer contained in the control card of the electric user HA; RB(Rectifier Bridge) indicates a diodes bridge used for rectifying theoutput voltage from the secondary of the transformer TF; FC (FilteringCapacitor) indicates a filter capacitor; VR (Voltage Regulator)indicates a voltage regulator and M2 indicates a microcontrollermanaging the control system of the electric user HA.

[0067] The receiver shown in FIG. 3a, being associated to the controlsystem of the electric user HA, decodes the network interruptionsproduced by the transmitter of FIG. 2 by means of two diodes D1 and D2,whose anodes are located at the terminals of the secondary of thetransformer TF.

[0068] The output half waves of the secondary of the transformer TF,rectified by the diodes D1 and D2, are applied to the base of atransistor TR1 through a resistive divider consisting of the resistorsR1 and R2, generating a positive pulse when the transistor TR1 is locked(0,6 Volt applied to the lower base).

[0069] As a result, upon absence of network interruptions, the signal Bin correspondence with the collector of the transistor TR1, applied tothe input SD of the microcontroller M2, is normally low, save around thezero crossing, where a positive pulse is generated as indicated in thegraphic representation of detail on the left side of FIG. 3a, of theoutput signal from the common cathodes of the diodes D1 and D2 amplifiedby the transistor TR1. For simplicity's sake, in this representation ofdetail, it has been considered the value of the resistor R2 as beingmuch higher than the one of the resistor R1; therefore, the transistorTR1 is deemed to be locked when the voltage on the cathodes of thediodes D1 and D2 is lower than 0,6 Volt.

[0070] More in general, since the amplitude of the above zero-crossingpulse depends upon the divider R1-2, the latter will be chosenaccordingly for the application, however, without any limits to thegenerality of the present invention.

[0071] On the contrary, in the presence of a network interruption, thesignal B on the collector of the transistor TR1 takes a high value,equal to Vcc (output voltage regulated at the voltage regulator VR) dueto the presence of a pull-up resistor, indicated with R3. The result isthe trend of the signal B (highlighted in the upper part of the graphchart in FIG. 3a), expressed as a function of the signal A (highlightedin the lower part of the same graph chart) and applied to the electricuser HA through the monitoring device SA.

[0072] As it can be easily noticed, the information (“Start”, logicvalue “one”, logic value “zero”) is contained within the duration of thesignal B which is generated in correspondence with the transistor TR1.

[0073] A second possible circuit embodiment for the receiver of networkinterruptions according to the present invention is represented in FIG.3b, where TF is the transformer of the control card of the electric userHA, RB is the diodes bridge employed for rectifying the output voltagefrom the secondary of the transformer TF, D1 is the diode used foruncoupling the output of the secondary of the transformer TF, FC is thefilter capacitor, VR is the voltage regulator and M2 is themicrocontroller managing the control system of the user HA.

[0074] Compared to the previous circuit embodiment, the half wavesexiting the transformer TF are rectified by the diodes bridge RB,instead of the two diodes D1 and D2 of FIG. 3a. The signal is suppliedto the base of the transistor TR1 always through the resistive dividerR1-R2.

[0075] As it can be noticed in the graphic representation of detail onthe left side of FIG. 3b, the signal B taken from the collector of thetransistor TR1 has a trend substantially matching the one alreadydescribed with reference to FIG. 3a.

[0076] Also, the graph chart in the lower part of FIG. 3b highlights thetrend of the signal B as a function of the signal A, which is analogousto the one shown in FIG. 3A, as it can be seen. In both solutions (FIG.3a and FIG. 3b), the signal applied to the input SD of themicrocontroller M2 is a digital signal and the various types ofinformation brought by the decoded signal are distinguished based on theduration of the pulse being produced.

[0077] With reference to the duration of the above pulse, threedifferent types of information can be distinguished:

[0078] 1. a short zero-crossing pulse, whose duration dependssubstantially on the value of the resistive divider R1-R2, which in thefigure corresponds to a logic “zero” being sent (assuming the choice ofa positive logic);

[0079] 2. a pulse, whose duration is equal to the network interruption,which in the figure corresponds to a fourth of the mains cycle,corresponding to a logic “one” being sent (assuming the choice of apositive logic);

[0080] 3. a start pulse, indicated with “Start”, whose duration is equalto a mains half cycle.

[0081] A third possible circuit embodiment of the receiver of networkinterruptions according to the present invention is represented in FIG.3c, where TF is the transformer of the control card of the electric userHA, RB is the diodes bridge employed for rectifying the output voltagefrom the secondary of the transformer TF, D1 is the diode used foruncoupling the output of the secondary of the transformer TF, FC is thefilter capacitor, VR is the voltage regulator and M2 is themicrocontroller managing the control system of the user HA.

[0082] The only difference compared to the circuit embodiment of FIG. 3bis that the signal applied to the input SD of the microcontroller M2 isan analogic signal instead of a digital signal. This signal, whoseamplitude is appropriately adapted to the input SD through the resistivedivider R1-R2, is decoded with the aid of an appropriateanalogic-digital converter being present within the microcontroller M2.

[0083] The upper part of the graph chart shown in FIG. 3c represents thetrend of the signal B expressed in function of the signal A, beinghighlighted in the bottom part of the same graph chart, applied to theelectric user HA through the monitoring device SA.

[0084] As it can be noticed, all the three circuit embodiment examplesof the receiver of network interruptions described above, have a minimumelectronic cost, matching in fact to that of a standard zero-crossingdetecting circuit. However, considering that such a circuit is anywayrequired for the normal operation of the control system of the electricuser HA, it is clear how the detection of the network interruptionsaccording to the present invention practically occurs at zero cost.

[0085]FIG. 6b represents by way of non limiting example a flowchartreporting a possible communication protocol to be adopted for receivingdigital information on electric network, transmitted through thetechnique of network interruptions, according to the embodiments of thepresent invention illustrated in the FIG. 3a, 3 b and 3 c.

[0086] Block 10 in this flowchart is a start block; block 11 is a testblock, wherein the control program checks the likely arrival of thesignal STX previously indicated with “Start”, which indicates thetransmission start by the control system of the monitoring device SA. Ifthe transmission start condition is not verified, then the controlremains at the block 11; otherwise, it is passes to block 12.

[0087] Block 12 is an initialization block of a counter N, wherein thenumber NBT of the bits provided in the transmission is stored.

[0088] The block 12 then releases the control to the block 13, which isa test block wherein the control program researches the synchronismcondition associated to the zero-crossing.

[0089] If the synchronism condition is not verified, the control remainsat the block 13; otherwise it goes on to the block 14, where the realreception process starts.

[0090] Block 14 is a test block, wherein the logic level of the receivedbit is verified. If the logic level corresponds to “1”, this value isstored in the corresponding register of the received bits; otherwise, ifthere is no pulse which can be associated to the logic “1” within themains half cycle (block 16, wherein the “time-out” variable is worth 10mSec when the mains frequency is 50 Hz), a “0” is stored (block 17).

[0091] Subsequently, the control goes on to block 18, where the valueinside the register N is decreased by one unit.

[0092] Then the block 19 follows, which is a test block, wherein theregister contents N is checked. If N is higher than zero, the controlgoes back to block 14 for acquiring the subsequent bit, whereas if N isequal to 0, the control goes to block 20, which is a test block checkingthe bits quality through the known checksum control technique.

[0093] Should the checksum verification have a negative result, thecontrol goes back to block 11, where the whole transmission is repeatedby the monitoring device SA; if this verification, vice-versa, issatisfactory, the control goes on to the block 21, which sends theacknowledge signal ACK of correct reception of digital informationtransmitted by the monitoring device SA.

[0094] Then the block 21 releases control to the block 22 of receptionend.

[0095] 1.3 Generalization of the Data Transmission Technique on ElectricNetwork Based on Modulation/Demodulation of the Supplied Power

[0096] A more general implementation of the data transmission techniqueon electric network described above with modulation/demodulation of thesupplied power may provide, according to the present invention, for theassociation of several bits to every mains voltage half wave. This maybe obtained, for example, by imposing a variable duration to eachnetwork interruption, expressed as a multiple of a basic duration D0(e.g. D0=0,1 mSec), corresponding to the weight of the lightest bit(bit0=2⁰*D0→0,1 mSec; bit1=2¹*D0→0,2 mSec; bit2=2²*D0+0,4 mSec;bit3=2³*D0→0,8 mSec).

[0097] In this case, the transmission speed may sensibly increasecompared to the previous basic example (association of one bit to eachhalf wave, with fixed duration of the network interruptions), dependingon the modulation mode being adopted.

[0098] Assuming, for simplicity's sake, the use of a positive logic, thecoding and the decoding of the binary data being transmitted orreceived, respectively, may be performed, according to the presentinvention in its more general version, adopting the following procedure.This coding/decoding procedure, indicated by way of non limitingexample, associates a “nibble”, i.e. a 4-bits binary configuration, toeach mains voltage half wave; some coding/decoding examples according tothe above procedure are as follows:

[0099] nibble==“0000”: transmission/reception of the decimal number“zero” associated to the total absence of a network interruption;

[0100] nibble—“0001”: transmission/reception of the decimal number “one”associated to the presence of a network interruption having a durationequal to 0,1 mSec;

[0101] nibble=“0011”: transmission/reception of the decimal number“three” associated to the presence of a network interruption having aduration equal to 0,3 mSec;

[0102] nibble=“0110”: transmission/reception of the decimal number “ten”associated to the presence of a network interruption having a durationequal to 1 mSec;

[0103] nibble=“1111”: transmission/reception of the decimal number“fifteen” associated to the presence of a network interruption having aduration equal to 1,5 mSec.

[0104] Therefore, the ensuing transmission speed is equal to 400 or 480bps, with reference to a mains frequency of 50 or 60 Hz, respectively.

[0105] 1.4 Case of Electric User Having a Control system SuppliedWithout a Voltage Transformer

[0106] In the particular event of an electric user HA fitted with anelectronic control system supplied directly from the mains through anappropriate impedance (such as of the type RC series) instead of atransformer, the transmission and reception procedure described abovehas to be restricted to one half wave alone: i.e. the one supplying theelectronic control system through the drop impedance of the mainsvoltage. In such an event, obviously, the quantity of information to besent in one second (baud-rate) is halved, but the transmission logicremains always the same, being fully included as a particular case inthe teachings of the present invention.

[0107] An example of a receiver of network interruptions like the onementioned just above, associated to an electric user HA fitted with anelectronic control system supplied directly by the mains voltage througha capacitive impedance is represented in FIG. 3d.

[0108] In this figure, DZ1 indicates a zener diode stabilizing thesupply voltage Vcc, FC is the filter capacitor, Z1 is the drop impedance(constituted by the connection in series of a capacitor C1 and aresistor R1′) supplying the system directly from the mains voltage; M2is the microcontroller of the control system of HA, R2′ is the resistor(with a high value: typically 1 megaohm) through which the zero-crossingsignal is picked up; D1′, D2′ and R3′ indicate the two diodes and theresistor protecting the input SD of the microcontroller M2 againstpossible transitory over voltages, respectively.

[0109] The synchronism signal picked up through the resistor R2′ andpresented, through R3′, at the input SD of the microcontroller M2typically consists, in the absence of network interruptions, of a squarewave with 50% duty-cycle and with cycle TR equal to the cycle associatedto the mains frequency (e.g.: TR=10 mSec, should the network frequencybe 50 Hz). In the presence of a network interruption, on the contrary,the temporary interval TRB between two subsequent positive edges will behigher compared to the mains cycle TR, as shown in the graphicrepresentation of detail on the left side of FIG. 3d.

[0110] In this instance, the useful information is associated to thehalf wave alone supplying the control system of HA and is contained, forexample, in the time interval separating a negative edge of the signal Bfrom its subsequent positive edge, so that the interval TU associated toa logic “one” is well separated from the interval TZ associated to alogic “zero”, as graphically represented in the bottom part of FIG. 3d.

[0111] It is clear that other circuit solutions, as well as otherpossible interpretation procedures of the coded information, arepossible for the man skilled in the art to the receiver of networkinterruptions without departing from the novelty spirit of theinvention.

[0112] Finally, it is also clear that a simplified receiver as describedabove may be advantageously applied by virtue of its minimum cost, alsoshould the electronic control system of the electric user HA be fittedwith a transformer, but not require a galvanic insulation between itslogic mass and the network voltage.

[0113]2. Second Technique of Data Transmission/reception on ElectricNetwork: Modulation of the Absorbed Power

[0114] The second technique of data transmission on electric networkaccording to the present invention uses, as coding means of binaryinformation, controlled absorptions of electric power, and is featuredby the two following essential elements:

[0115] a transmitter, capable of performing controlled absorptions ofelectric power in accordance with the binary information to betransmitted; a possible circuit diagram of this transmitter isillustrated in the upper part of FIG. 4;

[0116] a receiver, capable of detecting and decoding said absorptions ofelectric power; a possible circuit diagram of this receiver isillustrated in the upper part of FIG. 5.

[0117] The technique for transmitting data on electric network based onmodulation/demodulation of the absorbed power, according to a basicimplementation of the present invention, provides for the association ofone bit to each half wave of the mains voltage, to each power absorptionbeing imposed a value which is higher than a predetermined threshold SS(e.g, SS=3W).

[0118] In this instance, considering a mains frequency of 50 or 60 Hz,the data baud-rate equals 100 or 120 bps (bits per second),respectively.

[0119] 2.1 Description of the Transmitter of Controlled Absorption ofElectric Power

[0120] The description of the transmitter of controlled absorption ofelectric power according to the invention refers to FIG. 4.

[0121] According to the basic version of the present invention, thetransmitter comprised in the control system of the electric user HA isprogrammed for generating controlled absorptions of electric power withthe use of a solid state switch or relay, represented by the triacindicated with T1 in FIG. 4, whose activation signal O1 (applied to thegate) is managed by the microcontroller M2, supplied by means of avoltage regulator PS (Power Supply), and appropriately synchronized withthe signal ZD detecting the zero-crossing.

[0122] The triac T1 is associated to a generic electric load indicatedwith L1, appropriately chosen between the ones being available on theelectric user HA.

[0123] In the very particular event where the electric user HA shouldnot have any load being controlled through a triac (such as when allloads are managed by electromechanical relays), according to the presentinvention a low cost solution will be employed, which consists of asmall triac (such as a 0,8 A device in a plastic container T092) withassociated a low resistive electric load (e.g. 10 W).

[0124] As to the coding logic of the binary data to be transmitted,according to the basic version of the present invention, the followingtwo possible procedures are provided:

[0125] positive logic coding: a logic “1” corresponds to the presence ofan electric power absorption being higher than a predetermined thresholdSS (e.g. SS=3W) and a logic “0” corresponds to the absence of powerabsorption;

[0126] negative logic coding: a logic “0” corresponds to the presence ofan electric power absorption being higher than a predetermined thresholdSS (e.g. SS=3W) and a logic “1” corresponds to the absence of powerabsorption.

[0127] The graph chart shown in the lower part of FIG. 4 represents byway of non limiting example the transmission of a sequence of 8 bitsusing a positive logic coding, wherein the power absorptions, associatedto the logic “1”, equal half the instantaneous power associated to theload L1 and relate to a fourth of the mains cycle (5 mSec, should thenetwork frequency be 50 Hz).

[0128] This sequence of bits is preceded by a “Start” signal which, byway of non limiting example, is represented by an absorption equalingthe full power of the load L1, associated to a mains cycle (20 mSec,should the network frequency be 50 Hz). The upper part of the graphchart shows the voltage A at the terminals of the triac T1, whereas thebottom part of the graph chart shows the pulses O1 applied by themicrocontroller M2 to the gate of the same triac T1, in accordance withthe logic level of each bit to be transmitted. One of the possiblecommunication protocols to be adopted for transmitting digitalinformation on electric line according to the above technique, based oncontrolled absorptions of electric power is illustrated in the flowchartof FIG. 6a; therefore, as it can be noticed, this protocol can perfectlymatch the one associated to the transmitter of network interruptionspreviously described (par. 1.1—Description of the transmitter of networkinterruptions).

[0129] 2.2 Description of the Receiver of controlled absorptions ofElectric Power

[0130] The description of the receiver of controlled absorptions ofelectric power according to the present invention relates to FIG. 5,where PM (Power Meter) indicates a common power meter, S (Shunt)indicates a current resistive detector and M1 indicates the abovemicrocontroller fitting the monitoring device SA.

[0131] The microcontroller M1, which manages the receiver in themonitoring device SA according to the basic version of the presentinvention, detects the presence of electric power absorptions by theuser HA and determines their entity through the continuous metering ofthe power supplied in correspondence with each half wave of the mainsvoltage, through the device PM.

[0132] The decoding of the controlled absorptions of electric poweraccording to the present invention, represented by way of non limitingexample in the graph chart reported in the bottom part of FIG. 5, uses apositive logic (i.e. a logic “1” is associated to each power absorptionrelated to a half wave).

[0133] The bottom part of the graph chart represents the trend of themains voltage A measured at the terminals of the triac T1 employed forthe communication from the electric user HA, whereas the upper part ofthe graph chart represents the power B measured by the device PM.

[0134] The current detector S represented in FIG. 5, by way of nonlimiting example, is a precision resistor with a low thermal coefficient(e.g. S=5 mΩ 1%), whose voltage at the terminals (V2) is proportional tothe current crossing it, according to the known Ohm law.

[0135] More generally, according to the present invention, said detectorS may be represented by any other current detector (such as a currenttransformer, a Hall-effect sensor, and so on).

[0136] A possible communication protocol to be adopted for receivinginformation on electric network according to the above technique basedon controlled absorptions of electric power is illustrated in theflowchart of FIG. 6b; therefore, as it can be noticed, this protocol canperfectly match the one associated to the receiver of networkinterruptions previously described (see par. “Description of thereceiver of network interruptions). Finally, as to the decoding logic ofthe received binary data, according to the basic version of the presentinvention, the two procedures described above with reference to thetransmitter apply (see par. 2.1 Description of the transmitter ofcontrolled absolutions of electric power).

[0137] 2.3 Generalization of the Data Transmission Technique on ElectricNetwork Based on Modulation/Demodulation of the Absorbed Power

[0138] A more general implementation of the data transmission techniqueon electric network based on modulation/demodulation of the absorbedpower described above according to the present invention may provide forthe association of several bits to each half wave of the mains voltage.This may be obtained for example by imposing a value of variable entityto each controlled absorption of electric power, being expressed as amultiple of a basic absorption P0 (e.g. P0 1 Watt) corresponding to theweight of the lightest bit (bit0=2.9*P0→1W; bit1=2¹*P0→2W; bit2=2²*P0→4W; bit3=2³*P0→8W).

[0139] In this case, the transmission speed may sensibly increasecompared to the previous basic example (association of one bit to eachhalf wave); assuming the use of a positive logic, for simplicity's sake,according to a more general version of the present invention, codingand/or decoding of binary data transmitted or received, respectively,may be performed through the procedure described here below.

[0140] This coding/decoding procedure, indicated by way of non limitingexample, associates a nibble, i.e. a binary configuration of 4 bits, toeach half wave of the mains voltage; the following are a fewcoding/decoding examples according to the above procedure:

[0141] nibble=“0000”: transmission/reception of the decimal number“zero” associated to the absence of power absorption;

[0142] nibble=“0001”: transmission/reception of the decimal number “one”associated to a power absorption equal to 1 Watt;

[0143] nibble=“001”: transmission/reception of the decimal number“three” associated to a power, absorption equal to 3 Watt;

[0144] nibble=“0110”: transmission/reception of the decimal number “ten”associated to a power absorption equal to 10 Watt;

[0145] nibble=“1111”: transmission/reception of the decimal number“fifteen” associated to a power absorption equal to 15 Watt.

[0146] The ensuing transmission speed equals 400 or 480 bps, as for thecase described under par. 1.3, with reference to a network frequency of50 or 60 Hz, respectively.

[0147] 3. Examples of Use of the Poker Modulation Techniques Accordingto the Invention

[0148] As previously mentioned, considering that both the datatransmission techniques on electric network described above concernmodulation of the supplied power or absorbed power, this type ofmodulation is herein called power modulation.

[0149] The above data transmission techniques on electric network may beadvantageously used, according to the present invention, both in anindividual mode and in a combined mode; moreover, the present inventionmay be applied according to its basic version or to its more generalversion.

[0150] A particularly advantageous application employing a combinationof the two transmission techniques based on power modulation isdescribed in the following by way of non limiting example, according tothe basic version of the present invention (i.e. featured bytransmission/reception of one bit for each half wave of the mainsvoltage).

[0151] This application concerns the communication between twoelectronically controlled apparatuses, represented by an electric userHA and a monitoring device SA of the operation of the electric user,respectively, as already mentioned with reference to FIG. 1.

[0152] A second possible use of the present invention, particularlyadvantageous, obtained as a generalization of the previous one is thendescribed, and finally a third possible application based on the use ofthe transmission technique with controlled absorptions of electric poweronly is finally described.

[0153] 3.1 First Example of Use of the Power Modulation Techniques

[0154] As previously mentioned, FIG. 1 describes the mode of connectionbetween a monitoring device SA and a household electric user HA.

[0155] The device SA is interposed between the current outlet and theelectric user HA and performs a monitoring and control function of saidelectric user (as said above, the device SA may use the teachingsdescribed in U.S. Pat. No. 4,644,320 or EP-A-0 550 263).

[0156] According to the application of the invention described herein,the basic functions performed by the monitoring device SA are one ormore of the following ones:

[0157] a) metering of the electric current absorbed instant by instantby the electric user HA;

[0158] b) metering of the mains voltage applied to the electric user HA;

[0159] c) metering of the power factor (cost) of the electric loadrepresented by HA;

[0160] d) metering of the power absorbed instant by instant by theelectric user HA;

[0161] e) metering, and storing in a suitable non volatile memory, ofthe electric energy consumed by the electric user HA;

[0162] f) metering, and storing in a suitable non volatile memory, ofthe over voltages and brownouts of the mains voltage during a certaintime interval;

[0163] g) remote control of the electric user HA by means of a relay;

[0164] h) generation, and storing in a suitable non volatile memory, ofinformation relating to the operating status of the electric user HA;

[0165] i) generation, and storing in a suitable non volatile memory, ofstatistical data related to the operation of the electric user HA andmode of use by the person operating the electric user;

[0166] j) generation, and storing in a suitable non volatile memory, ofdiagnostic information related to the operation of the electric user HA,which are based on the trends of the electric quantities metered by SA;

[0167] k) dialog capacity with the external environment, throughappropriate communication technologies (power line, radio-frequency,two-wires cable, and so on).

[0168] A possible physical implementation of the device SA isrepresented in FIG. 7 illustrating the block diagram of the deviceitself and its mode of interconnection with an electric user HA,represented by a laundry washing machine.

[0169] The block PLM (Power Line Modem) represented in FIG. 7 isrealized, by way of non limiting example, using a transceiver PLT-22 byEchelon (USA), whose purpose is to warrant the bi-directional power linecommunication towards the external environment through the LonTalk®protocol (ANSI EIA-709). This protocol is implemented within the blockindicated with NC realized by a NeuronChip® device, currentlymanufactured by Toshiba and Cypress (LonTalk® and NeuronChip® areregistered trade-marks of the US company Echelon Inc.).

[0170] The set of blocks PLM and NC therefore forms the so-calledcommunication node, represented by the hatched block N in FIG. 7.

[0171] The block M1 (Microcontroller) is represented by way of nonlimiting example by any 8-bit microcontroller (preferably, but notnecessarily having a flash memory), whose purpose is to manage thedevice SA.

[0172] The block PS (Power Supply) is the block ensuring the stabilizedsupply to all the active elements of the device SA, in accordance withtheir electric specifications.

[0173] The block MEM is a memory block consisting, by way of nonlimiting example, of a non volatile memory of the eeprom type,appropriately connected to the microcontroller M1, wherein the latterstores all information obtained from the study of the trends of one ormore electric quantities associated to the operation of the electricuser HA, as detected by the metering block PM (Power Meter).

[0174] The block PM performs the important task of metering one or moreof the various electric quantities associated to the operation of theelectric user HA and communicate the metered value to themicrocontroller M1, to which it is appropriately connected.

[0175] The block PM is realized by way of non limiting example by meansof a device CS5460 by Cirrus Logic (USA), capable of metering current,voltage, power factor (cos φ), power and energy.

[0176] According to a much simpler and cost-effective version, the blockPM may simply consist of a current sensor, such as a resistive shunt ortoroid, whose generated voltage, being proportional to the currentabsorbed by the relevant electric user, is read by the microcontrollerM1 (directly or after appropriate amplification) through an appropriateanalog-digital conversion channel fitted on it.

[0177] It is clear that any other device PM having an intermediatecomplexity compared to the two limit cases described above, is fullyincluded in the aims of the present invention.

[0178] In the instance of the device PM described in FIG. 7, the primaryelectric quantities represented by the current absorbed by the load HAand the voltage applied to its terminals, are metered through themetering of the voltage V2 detected at the terminals of an appropriateresistive current sensor (resistive shunt or toroid or other currentdetector), indicated by the block S (Shunt), and voltage V1, as detectedthrough an appropriate resistive divider, not shown since it iscontained in the same block PM.

[0179] The derived electric quantities, such as cost, power and energyare then obtained through appropriate mathematical elaborationsperformed by the same device CS5460 of block PM, and made available tothe microcontroller M1 for likely further elaborations.

[0180] In FIG. 7, TCR indicates a block representing the triac T and thecontact RC of a normally closed relay, whose functions have beenpreviously described with reference to FIG. 2.

[0181] Finally, for a simpler description of the subsequent FIG. 8, theblocks PM, TCR and S of FIG. 7 are contained in a block PMR, which ishatched.

[0182] The block PM represents, according to the present invention, theblock for receiving the information transmitted by the user HA in theform of controlled absorptions of electric power, as for the techniquepreviously described; the block TCR represents, on the other side, theblock for transmitting by the monitoring device SA the informationcoded-through the network interruptions technique, previously described.

[0183] Vice-versa, the control system of the laundry washing machine HAcontains two appropriate functional blocks: one for transmitting digitalinformation using the technique based on controlled absorptions ofelectric power (see the previous description with reference to FIG. 4)and the other for receiving digital information sent by the monitoringdevice SA using the technique based on network interruptions (see theprevious description with reference to FIGS. 3a, 3 b and 3 c).

[0184] It should be noticed that, among the functions listed above, theitem “j” (generation of diagnostic information) represents one of themost significant functions of the device SA, being associated to thevery important concept of remote assistance and preventive maintenancefor the electric user HA.

[0185] However, this item is also a most critical one, because itpresumes the capacity for the monitoring device SA to detect anyfailures or malfunctions of the electric user HA in an indirect manner,i.e. only on the basis of the analysis of the values of the powerabsorptions and/or of other likely electric quantities that can bemetered by the meter PM.

[0186] Such a criticality might only be solved, according to the knownstate of art (such as described in U.S. Pat. No. 4,644,320 or EP-A-0 550263), through a direct dialog between the monitoring device SA and theelectric user HA, presuming the latter has an electronic control systemand self-diagnose capacity.

[0187] However, such a direct dialog cannot be easily obtained with theuse of known techniques, since they are too expensive (power linetransmission systems) or difficult to practice (direct connectionthrough a specific cable, which involves complexity and costs for themanufacture and installation of the electric users).

[0188] Applying, on the contrary, the power modulation transmissiontechniques covered by the present invention, the problem of a directdialog between the device SA and user HA can be fully and practicallysolved without additional costs.

[0189] In fact, going back to the application example of FIG. 1, theelectric user HA (in this case a laundry washing machine) can send dayby day to the device SA according to the present invention allinformation its electronic system is capable of obtaining or generating;to this purpose, the technique of the modulation/demodulation of theabsorbed power based on the controlled absorptions of electric powerwill be used.

[0190] The information may be stored, if necessary, in the memory blockMEM of the device SA of FIG. 7: let us think for example of diagnosticinformation, which can be made available later to the technical peopleentrusted with the assistance service for the user HA (e.g. by means ofa remote data elaboration center, through the block PLM managedaccording to the LonTalk® communication protocol).

[0191] Analogously, the monitoring device SA according to the presentinvention can send various information to the laundry washing machineHA, such as information relating to the power absorptions of its ownelectric loads (useful for diagnostic purposes) and other likelyinformation from the external environment (through the power linecommunication system represented in FIG. 7 with the hatched block N); tothis purpose, the technique of modulation/demodulation of the suppliedpower based on the network interruptions will be used.

[0192] By concluding, assuming that the device SA is appropriatelylocated within the cabinet of the laundry washing machine HA, the aboveapplication indicates a particularly efficient solution formanufacturing products capable of generating important information(energetic, functional, diagnostic and statistic) and make themavailable to the external environment through an appropriatecommunication system.

[0193] Finally, it should be pointed out that in agreement with theabove description of the device PM of FIG. 7 (which can coincide withthe one of FIG. 5), the accurate power measure (derived quantity)performed by the device CS5460 by Cirrus Logic can be replaced with asimple current measure (primary quantity), without departing from thenovelty spirit of invention.

[0194] In this case, in fact, the concept of “absorbed power” associatedto FIGS. 4 and 5 is simply replaced by the concept of “absorbedcurrent”, without jeopardizing in any way the present invention.

[0195] 3.2 Second Example of Use of the Power Modulation Techniques

[0196] A second possible application, using advantageously the two datatransmission techniques based on power modulation according to thepresent invention, is described in FIG. 8.

[0197] This figure represents the block diagram of a monitoring device,indicated as a whole with MSA (Multiple Smart Adapter), which isobtained as a generalization of the device SA described in theapplication of FIG. 1 or 7.

[0198] The device MSA is in fact derived from the device SA of FIG. 7;as it can be noticed, instead of the single block PMR of FIG. 7(comprising the block PM, the block TCR and the block S), the device MSAprovides for a set of blocks PMR, which in the specific case shown byway of non limiting example in FIG. 8, reach a total of five and areindicated with PMR1-PMR5.

[0199] As it can be noticed, the presence of several blocks PMR, managedby the same microcontroller (indicated with MC) through an appropriatebi-directional serial connection, allows for a simultaneous dialog witha corresponding number of electric users, indicated with HA1-HA5.

[0200] Since the most expensive part of the device SA is represented bythe communication node N, consisting as said above of the power linemodem of block PLM and of the Neuronchip of block NC of FIG. 7, a deviceMSA fitted with “k” blocks PMR (k=5 in the example of FIG. 8) will proveaccording to the invention far more convenient and easier to usecompared to independent “k” devices SA.

[0201] An example of practical use of a device MSA with four blocks PMRis represented in FIG. 9, where the relevant four electric users HA1-HA4are represented by a hob with hood, an electric oven, a dishwasher and arefrigerator, respectively.

[0202] As it can be imagined, this configuration is particularlyadvantageous in the field of built-in household appliances, i.e. forkitchen applications where the household appliances are integratedinside the furniture.

[0203] 3.3 Example of Use of the Technique Based onModulation/Demodulation of the Absorbed Power Only

[0204] A third example of application of the present invention, usingadvantageously only the data transmission technique based on thecontrolled absorptions of electric power, is illustrated in FIG. 10,wherein the electric user HA here represented by a householdrefrigerator, sends information to the external environment through itsown supply cord.

[0205] The electric load used for the data transmission through theabove controlled absorptions of electric power according to theinvention consists, by way of non limiting example, of the lamp of therefrigerating compartment, indicated with “LAMP” in the detail of FIG.10, controlled by means of the triac T, as per the procedures previouslydescribed with reference to FIG. 4.

[0206] This specific example indicates clearly how the use of the datatransmission technique based on controlled absorptions of electric poweraccording to the invention allows for manufacturing, practically withoutany additional costs, electric users capable of sending information tothe external environment without requiring any particular communicationnode.

[0207] Of course, in the example of FIG. 10, an appropriate receiverwill be associated to the electric network to which the refrigerator HAis connected with, capable of decoding the modulation of the electricpower absorbed by the load represented by the lamp LAMP.

[0208] From the above description the features of the present inventionare clear.

[0209] In particular, a method and a system for transmitting data onelectric network have been described, with particular reference to theexchange of binary information between two electric apparatuses, whichcan be obtained through two different techniques, usable in a singlemode or in a combined mode. For instance, the modulation of the suppliedpower can be well used for sending information to an electric user; themodulation of the absorbed power can be well used for sendinginformation by an electric user.

[0210] For both techniques, the binary information are coded through aparticular mode of “power modulation”.

[0211] The first data transmission technique, being identified as“modulation/demodulation of the supplied power” uses appropriatecontrolled interruptions or lacks of the electric network, defined as“network interruptions” or “voltage interruptions” as coding/decodingmeans of the binary information.

[0212] Vice-versa, the second data transmission technique, beingidentified as “modulation/demodulation of the absorbed power”, uses“controlled absorptions of electric powers” as coding/decoding means ofthe binary information.

[0213] The specific features of the method, the system and theapparatuses according to the present invention are summarized in theannexed claims.

[0214] From the above description also the advantages of the presentinvention are clear; once again it is underlined how the above method,system and relevant apparatuses for data transmission on electricnetwork can be implemented at a very low cost, also on the massproduction of household electric users, in particular household electricappliances.

[0215] It is clear that many changes are possible for the man skilled inthe art to the method, system and devices described above by way ofexample, without departing from the novelty spirit of the inventiveidea.

[0216] As previously mentioned, for instance, the transmitter associatedto the technique of modulation of the absorbed power can, in general, bebased on any electric load of the relevant user, provided is managed bya triac or similar controlled solid state switch.

[0217] Therefore, should the load have an excessive power, the controlsystem of the user would be programmed for applying only a minimumportion of the network voltage to such a load.

[0218] It is also clear that, should the user control system be capableof detecting a possible malfunction or failure of the transmission stageformed by the system “triac T+electric load L1” (see FIG. 4), the samecontrol system, duly programmed for that purpose, can decide the use ofanother “triac+electric load” stage for transmitting information to theexternal environment; this case is shown by way of example in FIG. 4,where L2 and LN indicate in fact further electric loads of the user HA,managed by respective triacs T2 and TN controlled by the microcontrollerM2, each one of them perfectly capable of generating controlled powerabsorptions according to the present invention, in alternative to T1.

[0219] As a result, should a malfunction of the “main” transmissionstage L1-T1 be detected, the control system of the user HA will beperfectly capable of signaling such a diagnostic problem to the externalenvironment through the technique of the modulation of the absorbedpower, using to the purpose one of the “secondary” stages (e.g. L2-T2).

[0220] The present invention has been described with a particularreference to its use in the field of household electric users, inparticular household electric appliances, but it is clear that itsapplication is possible in any field where a transmission or datacommunication between two electronically controlled electric apparatusesis useful or required.

1. Method for the transmission/reception or communication of data and/orinformation on electric line between two apparatuses having a respectiveelectronic control system (HA,SA;HA1-HA5,MSA), including: an electricuser (HA;HA1-HA5), in particular a household user, having a firstelectronic control system (M2) and at least a first electric load(L1;L2,LN); a monitoring or control device (SA;MSA), having a secondelectronic control system (M1;MC), said device (SA;MSA) being located onsaid line, between an electric power source (Outlet) and said firstelectric load (L1;L2,LN), characterized in that thetransmission/reception or communication of data or information on saidline is realized by means of a modulation of electric power between saiduser (HA;HA1-HA5) and said device (SA;MSA) and/or vice-versa.
 2. Method,according to claim 1, characterized in that the transmission/receptionor communication of data or information on said line from said user(HA;HA1-HA5) to said device (SA;MSA) is realized through a modulation ofthe electric power absorbed by said first load (L1;L2,LN), the powerabsorbed by said first load (L1;L2,LN) being controlled by said firstcontrol system (M2).
 3. Method, according to claim 1, characterized inthat the transmission/reception or communication of data or informationon said line from said device (SA;MSA) to said user (HA;HA1-HA5) isrealized through a modulation of the electric power supplied to saiduser (HA;HA1-HA5), the electric power supplied to said user (HA;HA1-HA5)being controlled by said second control system (M1;MC).
 4. Method,according to claims 2 and 3, characterized in that the bi-directionalexchange of data or information is provided between said device (SA;MSA)and said user (HA;HA1-HA5) on said line, the communication ofinformation from said device (SA;MSA) to said user (HA;HA1-HA5) beingrealized through said modulation of the supplied electric power and thecommunication of information from said user (HA;HA1-HA5) to said device(SA;MSA) being realized through said modulation of the absorbed electricpower.
 5. Method, according to claim 3 or 4, characterized in that saidmodulation of the supplied electric power uses, as coding means ofbinary information, controlled interruptions of the supply of theelectric mains from said device (SA;MSA) to said user (HA;HA1-HA5). 6.Method, according to claim 5, characterized in that the association ofone bit to each half wave of the mains voltage is provided, apredetermined duration being in particular set for each one of saidcontrolled interruptions relating to each half wave.
 7. Method,according to claim 5, characterized in that the binary data to betransmitted are coded with a positive logic, where a logic “one”corresponds to the presence of one of said controlled interruptions anda logic “zero” corresponds to its absence.
 8. Method, according to claim5, characterized in that the binary data to be transmitted are codedwith a negative logic, where a logic “zero” corresponds to the presenceof one of said controlled interruptions and a logic “one” corresponds toits absence.
 9. Method, according to claim 7 or 8, characterized in thatthe duration of said controlled interruptions equals a fraction of themains half cycle and, in particular, a fourth of the mains cycle. 10.Method, according to at least one of the previous claims, characterizedin that the sequence of bits forming the binary data to be transmittedis preceded by a transmission start signal (Start), represented inparticular by one of said controlled interruptions having a longerduration than the one being associated to a bit of real data, inparticular equaling a mains half cycle.
 11. Method, according to claim5, characterized in that the association of several bits to each halfwave of the mains voltage is provided.
 12. Method, according to claim11, characterized in that to each one of said controlled interruptions avariable duration is imposed, being in particular expressed as amultiple of a basic duration (D0).
 13. Method, according to claim 11 or12, characterized in that a 4-bit binary configuration, or “nibble” isassociated to each half wave of the mains voltage.
 14. Method, accordingto claim 2 or 4, characterized in that said modulation of the absorbedelectric power uses, as coding means of binary information, controlledabsorptions of electric power or current by said load (L1;L2,LN). 15.Method, according to claim 14, characterized in that the association ofone bit to each half wave of the mains voltage is provided, a valuebeing higher than a determined threshold being in particular imposed toeach one of said controlled absorptions.
 16. Method, according to claim14, characterized in that the binary data to be transmitted are codedwith a positive logic, where a logic “one” corresponds to the presenceof one of said controlled absorptions and a logic “zero” corresponds tothe absence of power absorption.
 17. Method, according to claim 14,characterized in that the binary data to be transmitted are coded with anegative logic, where a logic “zero” corresponds to the presence of oneof said controlled absorptions and a logic “one” corresponds to theabsence of power absorption.
 18. Method, according to claim 16 or 17,characterized in that said controlled absorptions are a fraction of themains half cycle, in particular equal to the instantaneous powerassociated to said load (L1) and relating to a fourth of the mainscycle.
 19. Method, according to claims 14 to 18, characterized in thatthe sequence of bits forming the binary data to be transmitted ispreceded by a transmission start signal (Start), in particularrepresented by a power absorption equal to the fall power of said load(L1), associated to a mains cycle.
 20. Method, according to claim 14,characterized in that the association of several bits to each half waveof the mains voltage is provided.
 21. Method, according to claim 20,characterized in that a value of variable quantity is imposed to eachone of said controlled absorptions, expressed in particular as amultiple of a basic absorption (P0).
 22. Method, according to claim 20or 21, characterized in that a 4-bit binary configuration, or “nibble”,is associated to each half wave of the mains voltage.
 23. Method,according to at least one of claims from 14 to 22, characterized in thatsaid first control system (M2) applies only a portion of the mainsvoltage to said load (L1;L2,LN).
 24. System for thetransmission/reception or communication of data or information onelectric line between two apparatuses having a respective electroniccontrol system (HA,SA;HA1-HA5,MSA), including: an electric user(HA;HA1-HA5), in particular a household user, having a first electroniccontrol system (M2) and at least a first electric load (L1;L2,LN); amonitoring or control device (SA;MSA), having a second electroniccontrol system (M1;MC), said device (SA;MSA) being located on said line,between an electric power source and said first electric load(L1;L2,LN), characterized in that means are provided for realizing thetransmission/reception or communication of data or information on saidline through a modulation of electric power between said user(HA;HA1-HA5) and said device (SA;MSA), and/or vice-versa.
 25. System,according to claim 24, characterized in that said means comprise atransmission stage or transmitter (T,RC,G,ZD) of said device (SA;MSA),controlled by said second control system (M1;MC) and programmed forrealizing a modulation of the electric power supplied by said device(SA;MSA) to said user (HA;HA1-HA5).
 26. System, according to claim 25,characterized in that said means comprise a reception stage or receiver(D1,D2,R1-R3,TR1,SD; RB,R1-R3,TR1,SD; RB,R1,R2,SD;DZ1,C1,R1′-R3′,D1′D2′) of said user (HA;HA1-HA5), controlled by saidfirst control system (M2) and programmed for decoding said modulation ofthe electric power supplied by said device (SA;MSA).
 27. System,according to claim 1, characterized in that said means comprise atransmission stage or transmitter (L1,T1,01; L2,T2,O2,LN,TN,LN) of saiduser (HA;HA1-HAS), controlled by said first control system (M2) andprogrammed for realizing a modulation of the electric power absorbed bysaid first load (L1;L2,LN).
 28. System, according to claim 27,characterized in that said means comprise a reception stage or receiver(PM,S,ZD) of said device (SA;MSA), controlled by said second controlsystem (M1;MC) and programmed for decoding said modulation of theelectric power absorbed by said first load (L1;L2,LN).
 29. System,according to claims 25 to 28, characterized in that: said device(SA;MSA) comprises both said transmitter (T,RC,G,ZD) and said receiver(PM,S,ZD); said user (HA,HA1-HA5) comprises both said receiver(D1,D2,R1-R3,TR1,SD; RB,R1-R3,TR1,SD; RB,R1,R2,SD;DZ1,C1,R1′-R3′,D1′D2′) and said transmitter (L1,T1,01; L9,T2,O2,LN,TN,LN).
 30. System, according to claim 24 or 29, characterized in that saidtransmitter of said device (SA;MSA) comprises means (T,RC,G,ZD) forcoding binary information by means of controlled interruptions of thesupply of the electric mains from said device (SA;MSA) to said user(HA;HA1-HA5).
 31. System, according to claim 30, characterized in thatsaid coding means (T,RC,G,ZD) comprise a solid state switch or relay, inparticular a triac (T), whose enabling signal (G) is synchronized with asignal (ZD) detecting the mains voltage zero-crossing.
 32. System,according to claim 31, characterized in that said solid state switch orrelay (T) is in parallel to the normally closed contact (RC) of anelectromechanical relay.
 33. System, according to claims 31 and 32,characterized in that said electromechanical relay (RC), said solidstate switch or relay (T) and said synchronism signal (ZD) are managedby a microcontroller (M1;MC) being part of said second control system.34. System, according to claim 26 or 29, characterized in that saidreceiver of said user (HA,HA1-HA5) comprises means (D1,D2,R1-R3,TR1,SD;RB,R1-R3,TR1,SD; RB,R1,R2,SD; DZ1,C1,R1′-R3′,D1′D2′) for decoding binaryinformation produced by said controlled interruptions.
 35. System,according to claim 34, characterized in that said decoding means(D1,D2,R1-R3,TR1,SD; RB,R1-R3,TR1,SD; RB,R1,R2,SD; DZ1,C1,R1-R3′,D1′D2′)comprise two diodes (D1,D2), whose anodes are located in particular atthe terminals of the secondary of a transformer (TF) of said firstcontrol system (M2).
 36. System, according to claim 35, characterized inthat the half waves exiting the secondary of said transformer (TF),rectified by said diodes (D1,D2), are applied to the base of atransistor (TR1) through a resistive divider (R1,R2), for generating apulse applied to a digital signal input (SD) of a microcontroller (M2).37. System, according to claim 34, characterized in that said decodingmeans (D1,D2,R1-R3,TR1,SD; RB,R1-R3,TR1,SD; RB,R1,R2,SD;DZ1,C1,R1′-R3′,D1′D2′) comprise a diodes bridge (RB) for rectifying thehalf waves exiting a transformer (TF) of said first control system (M2),and apply them to the base of a transistor (TR1) through a resistivedivider (R1,R2), for generating a pulse being directed to a digitalsignal input (SD) of a microcontroller (M2).
 38. System, according toclaim 34, characterized in that said decoding means (D1,D2,R1-R3,TR1,SD;RB,R1-R3,TR1,SD; RB,R1,R2,SD; DZ1,C1,R1′-R3′,D1′D2′) comprise a diodesbridge (RB) for rectifying the output voltage of the secondary of atransformer (TF) of said first control system (M2) and generate througha resistive divider (R1,R2) a signal applied to an analogic signal input(SD) of a microcontroller (M2).
 39. System, according to claim 27 or 29,characterized in that said transmitter of said user (HA;HA1-HA5)comprises means (L1,T1,01; L2,T2,O2,LN,TN,LN) for coding binaryinformation by means of controlled absorptions of electric power orcurrent by said first load (L1;L2,LN).
 40. System, according to claim39, characterized in that said coding means comprise a solid stateswitch or relay, such as a triac (T1;T2,TN), associated to said firstelectric load (L1;L2,LN).
 41. System, according to claim 40,characterized in that the enabling signal (O1;O2,ON) of said solid stateswitch or relay (T1;T2,TN) is managed by a microcontroller (M2) andsynchronized with a signal (ZD) detecting the mains voltagezero-crossing.
 42. System, according to claim 28 or 29, characterized inthat said receiver of said device (SA;MSA) comprises means (PM,S,ZD) fordecoding binary information produced by said controlled absorptions. 43.System, according to claim 42, characterized in that said decoding means(PM,S,ZD) comprise an electric power meter (PM).
 44. System, accordingto claim 42, characterized in that said decoding means (PM,S,ZD)comprise a current detector (S).
 45. System, according to claim 43,characterized in that said second control system (M1;MC) is programmedfor detecting the presence of power absorptions by said load (L1;L2,LN)and determining their entity through a continuous measure of thesupplied power or current in correspondence of each half wave of themains voltage, performed by means of said power meter (PM).
 46. System,according to at least one of claims 43 to 45, characterized in that saidpower meter (PM) comprises an integrated circuit, in particular a CS5460Cirrus Logic circuit.
 47. Monitoring or control device implementing themethod according to one or more of claims 1 to 23 and/or for its use inthe system according to one or more of claims 24 to
 46. 48. Device,according to claim 47, characterized in that it comprises: means (PM,S)for metering the electric current absorbed instant by instant by saiduser (HA;HA1-HA5), and/or means (PM) for metering the mains voltageapplied to said user (HA;HA1-HA5), and/or means (PM) for metering thepower factor (cost) of the electric load represented by said user(HA;HA1-HA5), and/or means (PM,S) for metering the power absorbedinstant by instant by said user (HA;HA1-HA5), and/or means (PM) formetering the electric energy consumed by said user (HA;HA1-HA5), and/ormeans (PM) for metering the over voltages and the brownouts of the mainsvoltage during a given time interval, and/or means (N,RC) for the remotecontrol of said user (HA;HA1-HA5), and/or means (M1) for generatinginformation concerning the operating status of said user (HA;HA1-HA5),and/or means (MI) for generating statistical data concerning theoperation of said user (HA;HA1-HA5) and/or mode of use by the personoperating said user, and/or means (M1) for generating diagnosticinformation concerning the operation of said user (HA,HA1-HA5), and/ordialog means with the external environment (N), in particular through apower line system.
 49. Device, according to claim 47 and/or 48,characterized in that it comprises a communication node (N).
 50. Device,according to claim 49, characterized in that said communication node (N)comprises a modem (PLM), in particular a transceiver PLT-22 Echelon(USA), for the bi-directional power line communication through the.LonTalk® protocol (ANSI EIA-709).
 51. Device, according to claim 49,characterized in that said communication node comprises an integratedcircuit, in particular of the NeuronChip® type.
 52. Device, according toat least one of the previous claims, characterized in that it comprisesmemory means (MEM), in particular an non volatile memory of the eepromtype, wherein information or data coming from said user (HA;HA1-HA5) arestored.
 53. Device, according to at least one of the previous claims,characterized in that it comprises a plurality of said electric powermeters (PM).
 54. Device, according to at least one of the previousclaims, characterized in that it comprises a plurality of said currentdetectors (S).
 55. Device, according to at least one of the previousclaims, characterized in that it comprises a plurality of saidtransmitters (T,RC,G,ZD) for realizing a control or modulation of theelectric power supplied to a corresponding number of electric users(HA1-HA5).
 56. Device, according to at least one of the previous claims,characterized in that it comprises a plurality of said receivers(PM,S,ZD) for decoding the modulation of the electric power absorbed bysaid first load (L1;L2,LN) of a corresponding number of electric users(HA1-HA5).
 57. Electric user, in particular a household appliance,implementing the method according to one or more of claims 1 to 23and/or for its use in the system according to one or more of claims 24to
 46. 58. User, according to claim 57, characterized in that itcomprises a plurality of said transmitters (L1,T1,01,L2,T2,O2,LN,TN,LN),being of alternative use, and that said first control system (M2) isprogrammed for detecting likely malfunctions of at least a first one(L1,T1,01) of said transmitters and consequently utilize a second one ofsaid transmitters (L2,T1,O2,LN,TN,LN) for the purposes of transmissionor communication of data or information.